BRIEF [O.A.] Reichenfeld, Soma Author: Reichenfeld, Soma Recipient: Haeckel, Ernst Dating: 04.06.1910
POSTKARTE Huzella, Julius Author: Huzella, Julius Recipient: Haeckel, Ernst Corporation: Handels- und Gewerbe-Kammer
BRIEF [O.A.] Holitscher, Ph... Author: Holitscher, Ph... Recipient: Haeckel, Ernst Dating: 19.11.1898
BRIEF [O.A.] Hartmann, S... E... Author: Hartmann, S... E... Recipient: Haeckel, Ernst Dating: 19.12.1913
